1. Field of the Invention
The present invention generally relates to a hybrid vehicle drive control apparatus for a hybrid vehicle having an electric drive (EV) mode a hybrid drive (HEV) mode. More specifically, the present invention relates to a hybrid vehicle drive control apparatus for a hybrid vehicle that changes an EV drive region in accordance with degradation of an electric power source.
2. Background Information
In recent years, advances are being made in the development of hybrid vehicles that use an engine and a battery as power sources. In particular, numerous hybrid vehicle technologies are being developed in relation to a state of charge (SOC) and a degradation state of a battery used as an electric power source. For example, there is a known control technology that varies the input and output power of a battery of a hybrid vehicle in accordance with a degree of degradation of the battery (e.g., see Japanese Laid-Open Patent Publication No. 2000-125415). There is also a known control technology that changes a threshold value used to determine if an idle stop should be permitted in a hybrid vehicle having a battery. This control changes the threshold value to a value corresponding to a higher battery SOC when the battery of the hybrid vehicle has become degraded (e.g., see Japanese Laid- Open Patent Publication No. 2001-268708).
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved hybrid vehicle drive control apparatus. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.